Comments: 5 pages, 4 figures, to appear in the Proceedings of the Marseille 2001 Conference: Where's the matter? Tracing dark and and bright matter with the new generation of large scale surveys, Treyer & Tresse, eds

Comments: 6 pages, 2 figures, uses edp-jp4.cls, to appear in the Proceedings of the Summer School "GAIA: a European Space Project", held on the 13-18 May 2001 at the Ecole de Physique des Houches, Les Houches, France, published in the "Journal de Physique IV", EDP Sciences

Comments: Revised to include additional material, requested by the MNRAS referee, on the photometric calibration of the 2dFGRS and surface brightness dependencies. Full resolution figures and additional material at this http URL